In a large pot or Dutch oven, melt butter over medium heat. Add diced onion and celery, cooking until softened (about 5 minutes). Stir in the garlic and cook for 1 minute until fragrant.
Pour in the chicken broth and bring to a simmer. Stir in shredded chicken and buffalo sauce. Let it simmer for 5–10 minutes to blend flavors.
Add cream cheese and ranch (or blue cheese) dressing, stirring until melted and smooth. Then add shredded cheddar and heavy cream. Stir until fully combined and heated through. Season with salt and pepper to taste.
Let the soup simmer for another 5–10 minutes to thicken slightly. Ladle into bowls and top with your favorite garnishes like green onions, crumbled blue cheese, or crispy bacon.